21666532430 has 8 divisors (see below), whose sum is σ = 38999758392. Its totient is φ = 8666612968.

The previous prime is 21666532429. The next prime is 21666532549. The reversal of 21666532430 is 3423566612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1083326612 + ... + 1083326631.

It is an arithmetic number, because the mean of its divisors is an integer number (4874969799).

Almost surely, 2^21666532430 is an apocalyptic number.

21666532430 is a deficient number, since it is larger than the sum of its proper divisors (17333225962).

21666532430 is a wasteful number, since it uses less digits than its factorization.

21666532430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2166653250.

The product of its (nonzero) digits is 155520, while the sum is 38.

The spelling of 21666532430 in words is "twenty-one billion, six hundred sixty-six million, five hundred thirty-two thousand, four hundred thirty".